Criticism that the State Department is being hollowed out really irks the man blamed for it, Secretary of State Rex Tillerson.

"There is no hollowing out," Tillerson said somewhat defensively on Tuesday when asked about it during a question-and-answer session after he gave a speech at the Wilson Center in Washington. "These numbers that people are throwing around are just false. They're wrong."

For months now, questions about sagging morale and planned staff cuts at Foggy Bottom have stalked Tillerson. Dozens of senior diplomats have quit or taken early retirement. Some left feeling pushed out. Many senior positions are filled temporarily by people who have the word "acting" in their titles, and some leadership positions are already in their second and third rotation.

As journalists have chronicled the churn, members of Congress have written letters to Tillerson complaining they have not been kept informed. Former diplomats and the Foreign Service officers' union have raised alarms about the potential for downsizing in such a perilous time, and questioned whether the department will be crippled for years to come.

Tillerson probably saw the question coming, once again, after his speech. On Monday, a former corporate executive Tillerson hired in August to oversee the reorganization he calls a redesign abruptly quit. Maliz Beams was the third person assigned the job Tillerson recently called the most important task he will accomplish during his tenure, and though she was not widely known within the building, her departure only raised more questions.

Also Monday, two distinguished former diplomats, Nicholas Burns and Ryan Crocker, wrote an opinion piece in the New York Times decrying what they characterized as the brain drain of so many experienced diplomats. They said Tillerson's proposal for an 8 percent staff cut, ordered by the White House, was not just belt-tightening but was a deliberate effort to "dismantle" the State Department.

With the criticism fresh, Tillerson seemed prepared to push back on Tuesday.

"We're keeping the organization fully staffed," he said, calling the 2016 budget of almost $55 billion a record high that is not sustainable.

Tillerson said he was "stunned" when he arrived in February and saw an organizational chart with 82 senior diplomats reporting directly to him.

But after going through three reorganizations at ExxonMobil — "I enjoy doing it," Tillerson saidTuesday — he realized he was uniquely prepared to restructure State for the 21st century. At the end, he said, the work would be more effective and personally satisfying to employees.

But Tillerson said reports describing the changes underway have overstated the turmoil. The total number of employees is about the same, largely because he has approved more than 2,300 exemptions to the hiring freeze and turned down only eight. Although the number of career ambassadors, the most elite diplomats in the Foreign Service, is down more than 60 percent, the raw numbers are small — just two remain after four retired.

"It sounded like the sky was falling," he said.

Tillerson called the complaints offensive to the employees.

"I am offended on their behalf when people say somehow we don't have a State Department that works," he said. "I can tell you it's functioning very well from my perspective."

But the resignation of Beams served to underscore a State Department that often appears to be struggling. The redesign is still something of a mystery despite Tillerson's touting it almost from the day he arrived. Some 35,000 employees have filled out questionnaires, and about 300 have been interviewed more in depth. Now, in phase three, the department is holding workshops on topics such as technology and organizational structure.

But there is still no timeline for when the work will be completed. Lawmakers on important committees overseeing the State Department complain they don't know what's happening. And if a grand vision has been set as a goal, few among the rank and file say they know what it is.

State Department spokeswoman Heather Nauert said Beams told her Monday she came to "set the vision" for the redesign, and she accomplished it in her 14 weeks on the job. "I feel good about it," Nauert quoted Beams telling her.